Book/Report

FZJ-2018-03464

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Hadronische Spinanregungen in endlichen Fermionensystemen

Unkelbach, W. (Corresponding author)FZJ*

1991
Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag Jülich

Please use a persistent id in citations: http://hdl.handle.net/2128/18902

Report No.: Juel-2477

Abstract: Hadronic spin-excitations in finite Fermi systems are investigated by studying inelastic proton- and antiproton-nucleus scattering in doubly magic nuclei ($^{12}$C, $^{40}$Ca, $^{48}$Ca, $^{208}$Pb). The Random-Phase-Approximation (RPA) and the Distorted-Wave-Born-Approximation (DWBA) are used to describe the nuelear structure and reaction respectively. The possibility of a low-energy octupole resonance (LEOR) in $^{208}$Pb, which exhausts a significant fraction of the energy weighted sum rule, is investigated. lt is found that the sum-rule fraction of $\sim$ 15% seen in (p,p ') reactions depends sensitively on the strength of the isovector projectile-target nucleus interaction. To study spin-excitations in (p,p ')-reactions, the double differential cross section and the spin-flip pobability S$_{yy}$ are calculated for forward angles. They are in good agreement with experiments on $^{40}$Ca, $^{48}$Ca and $^{208}$Pb at intermediate incident energies (200 MeV- 800 MeV). The experimentally observed spin-dipole resonance in $^{40}$Ca can be reproduced. S$_{yy}$ depends sensitively on the distorsions of the projectile wave. Different versions of the N$\overline{N}$-potential of the Bonn-Jülich group have been used to calculate ($\overline{p}$,$\overline{p}$') cross sections on $^{12}$C. They show large sensitivity for unnatural parity states . Because of the strong absorption, this reaction is an excellent probe for the Jong-range one-pion exchange.

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Contributing Institute(s):

1. Publikationen vor 2000 (PRE-2000)

Research Program(s):

1. 899 - ohne Topic (POF3-899) (POF3-899)

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